Please no Cory in a 10g!!! Cory's are to be kept in groups of at LEAST 8 - Apart from that they grow to be (pending exact species) anywhere from 3-6", so 8x6" Cory in a 10g them guys couldn't move in there and that is a less then desirable habitat!!! So def no tank smaller then 20g I'd strongly suggest.

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groups of 8? I always kept corys in groups of 4 but im not expert on them. They are really cool fish the way they scury along the bottom looking for food. Thier so animted rarely staying still for long. I know not all species of cory grow 3-6"? I've never seen a cory over 3 and rarely. There are alot of species out there. I know Corydoras hastatus don't grow more than 1.5in and might work. I don't want to contradict Angel079 too much because im not an expert on corys.

I agree with RRcoolJ.............you can keep them in smaller numbers than 8, but i would think 5 should be the minimum..........I'm at a loss to think of any species of cory that would get any bigger than 4 inches......as stated, i think most would max out at around 3 inches